The present invention relates to a motor vehicle chassis and in particular a chassis of a beam type exhibiting high passive security characteristics in case of an impact.
Motor vehicle chassis comprising a central steel beam with a very strong section onto which the members supporting the principal organs and the body of the vehicle are attached are already known.
This type of chassis, called hereinafter a beam type chassis, has, however, numerous disadvantages due in particular to its great weight which requires significant power to set it into motion and to its great rigidity which obstructs deformation which is essential for the absorption of energy in case of an impact. Indeed, no part of the chassis is designed to absorb the impact energy produced in the event of an accident so that the whole of this energy is transmitted to the occupants via the passsenger space of the vehicle.
These disadvantages subsequently led to the development of a new type of vehicle in which the chassis and the body are combined. This chassis-body assembly, which is still used today, is called a monoshell or self-supporting body, and includes a chassis-frame formed of a certain number of elements of pressed sheet metal welded together and a superstructure formed in the same manner and assembled either in a rigid or elastic way on the chassis-frame.
Although this type of chassis offers a good compromise between lightness and rigidity, giving it advantageous safety features, it has, however, a large number of pieces that have to be assembled during numerous welding operations, which even if they are performed by robots, make the manufacturing costs of the chassis-frame high. This is why research is constantly carried out to provide the public with a simple motor vehicle chassis with increased safety features.